WL#1972 "Evaluate HAVING before SELECT select-list"

- post-review fix regarding Item_fields
- added test for the changed name resolution


mysql-test/r/having.result:
  Test for changed name resolution of Item_fields
mysql-test/t/having.test:
  Test for changed name resolution of Item_fields
sql/item.cc:
  - Changed Item_field::fix_fields to perform the same name
    resolution as Item_ref::fix_fields because column references
    of subqueries inside HAVING may be represented as Item_fields,
    and they need to be resolved as Item_refs.
  - Adjusted Item_field::fix_fields so that it has the same variable
    names and structure as Item_ref::fix_fields.

1 files changed, 7 insertions, 0 deletions

diff --git a/mysql-test/r/having.result b/mysql-test/r/having.result
index 6f548d20668..86c9adf8cf6 100644
--- a/mysql-test/r/having.result
+++ b/mysql-test/r/having.result
@@ -245,6 +245,13 @@ col1
 10
 10
 10
+select sum(col1) from t1
+group by col_t1
+having (select col_t1 from t2 where col_t1 = col_t2 order by col_t2 limit 1);
+sum(col1)
+40
+20
+30
 select t1.col1 from t1
 where t1.col2 in 
 (select t2.col2 from t2